Polymer Brushes on Single-Walled Carbon Nanotubes by Atom Transfer Radical Polymerization of n-Butyl Methacrylate
Top Cited Papers
- 10 December 2003
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 126 (1), 170-176
- https://doi.org/10.1021/ja037937v
Abstract
Polymer brushes with single-walled carbon nanotubes (SWNT) as backbones were synthesized by grafting n-butyl methacrylate (nBMA) from the ends and sidewalls of SWNT via atom transfer radical polymerization (ATRP). Carboxylic acid groups on SWNT were formed by nitric acid oxidation. The ATRP initiators were covalently attached to the SWNT by esterification of 2-hydroxyethyl 2‘-bromopropionate with carboxylic acid groups. Methyl 2-bromopropionate (MBP) was added as free initiator during the brush preparation to control growth of the brushes and to monitor the polymerization kinetics. Size-exclusion chromatography (SEC) results show that the molecular weight of free poly(n-butyl methacrylate) (PnBMA) increased linearly with nBMA monomer conversion. PnBMA cleaved from the SWNT after high conversion had the same molecular weight as PnBMA produced in solution. Thermogravimetric analyses (TGA) show that the amount of PnBMA grown from the SWNT increased linearly with the molecular weight of the free PnBMA. The most highly PnBMA-functionalized SWNT dissolve in 1,2-dichlorobenzene, chloroform, and tetrahydrofuran, and solubility increases with the amount of PnBMA bound to SWNT. Near-infrared and Raman spectra indicate that the side walls of the SWNT were lightly functionalized by the nitric acid treatment and that the degree of functionalization of the SWNT did not change significantly during the formation of initiator or during the polymerization. Atomic force microscopy (AFM) images show contour lengths of the SWNT brushes on a mica surface from 200 nm to 2.0 μm and an average height of the backbone of 2−3 nm, indicating that the bundles of original SWNT were broken into individual tubes by functionalization and polymerization.Keywords
This publication has 40 references indexed in Scilit:
- Super-tough carbon-nanotube fibresNature, 2003
- Effect of Initiation Conditions on the Uniformity of Three-Arm Star Molecular BrushesMacromolecules, 2003
- Structure-Assigned Optical Spectra of Single-Walled Carbon NanotubesScience, 2002
- Carbon Nanotubes--the Route Toward ApplicationsScience, 2002
- Atom Transfer Radical PolymerizationChemical Reviews, 2001
- Polymer brushes: surface-immobilized macromoleculesProgress in Polymer Science, 2000
- Ring-Opening Metathesis Polymerization from SurfacesJournal of the American Chemical Society, 1999
- Surface-Initiated Anionic Polymerization of Styrene by Means of Self-Assembled MonolayersJournal of the American Chemical Society, 1999
- Controlling Polymer-Surface Interactions with Random Copolymer BrushesScience, 1997
- Forces between surfaces of block copolymers adsorbed on micaJournal of the American Chemical Society, 1986